Abstract: A suitable inert gas such as argon or a mixture of inert and reactive gases such as argon and hydrogen is introduced onto the backside of wafers being processed in a CVD reactor during the deposition of tungsten or other metals, metal nitrides and silicides, to avoid deposition of material on the backside of the wafers being processed. Each process station includes a gas dispersion head disposed over a platen. A vacuum chuck including a number of radial and circular vacuum grooves in the top surface of the platen is provided for holding the wafer in place. A platen heater is provided under the platen. Backside gas is heated in and about the bottom of the platen, and introduced through a circular groove in the peripheral region outside of the outermost vacuum groove of the vacuum chuck. Backside gas pressure is maintained in this peripheral region at a level greater than the CVD chamber pressure.

Abstract: A thin film resistor is formed using sputtering to deposit a thin film of resistive material on an insulating surface. The sputter target is composed of constituents which are normally present in relatively large quantities in thin film resistors, such as chromium silicide and silicon carbide. The sputtered thin film material is formed into resistor regions. An insulating layer is deposited over the thin film material. Ions (e.g., boron ions) are then implanted into the thin film through the insulating layer. These implanted constituents have a significant effect on the temperature coefficient and sheet resistance of the thin film resistor. Ion implantation of these constituents enables more control over the characteristics of the thin film resistor as compared to prior art techniques not using ion implantation.

Abstract: In the disclosed method, a transistor is fabricated by depositing an unpatterned layer of silicon on an insulating layer over a surface of a semiconductor substrate, with the silicon layer being deposited in an amorphous state to improve its uniformity in thickness and smoothness. Subsequently, while the silicon layer is still in the amorphous state, it is patterned by removing selected portions to form a gate. This patterning in the amorphous state improves the gates edge definition. Thereafter, the patterned amorphous silicon layer is heated to change it to polycrystalline silicon, thereby increasing its stability and conductivity.